Barring any last-minute change of plans, President Muhammadu will on Wednesday depart for South Africa, presidency sources have told PREMIUM TIMES.
The visit is Mr Buhari's first since the recent xenophobic attacks in South Africa, targetting foreigners.
Mr Buhari is expected to be in South Africa till Friday.
The relationship between Nigerian and South Africa went sour following the xenophobic attacks on Nigerians and other Africans.
About a dozen people were killed in the attacks.
Although the Nigerian government said no Nigerian was killed in the latest attacks, it confirmed that several businesses owned by Nigerians were destroyed.
The Nigerian government in response withdrew from the World Economic Forum in South Africa, and encouraged its citizens in South Africa to return. The government also demanded compensation for victims of the attack and an integrated security for Nigerians in South Africa that would include Nigerian officials.
The government, however, condemned retaliatory attacks on South African businesses in Nigeria.
There is no indication the South African government has met any of Nigeria's two demands of compensation and integrated security for its citizens.
As the South African government tried to assuage the feelings of its African neighbours, some of its officials blamed the leaders of those countries for the xenophobic attacks.
"We cannot absorb the results of all the problems that are made by leaders who want to loot their countries, who do not care about their own people," Blade Nzimande, the South African minister of higher educations, science and technology, said in Durban, while commenting on the bashing of his country over the xenophobic attacks.
Mr Nzimande's remarks, reported by Sowetan Live, a South African news website, coincided with the tendering of an apology to the people and government of Nigeria by President Cyril Ramaphosa's Special Envoy to Nigeria, Jeff Radebe.
Since the recent attacks, over 300 Nigerians have voluntarilty returned from South Africa via a free travel by Air Peace.
History of Xenophobia
Over the years, violent attacks on Nigerians and other Africans have regularly erupted in South Africa mostly because South Africans accuse foreigners of dealing in drugs or taking their jobs.
The most recent xenophobic attacks started in the first week of September in parts of South Africa.
Since the attacks, President Buhari has sent a special envoy to South Africa. The envoy held discussions with President Cyril Ramaphosa on September 6.
Mr Ramaphosa later sent his peace envoy to Nigeria over the xenophobic attacks.
Reating to the attacks, former Nigerian President Olusegun Obasanjo urged countries whose citizens were affected in the xenophobic attacks in South Africa to take the matter to the African Union (AU) for redress.
"As a suggestion, South Africa should send emissaries to the countries concerned to explain, apologise and agree on the way forward for mutual understanding, accommodation, reconciliation, and binding the wound to promote unity, concord, and brotherhood in Africa."
Also, Nigerians living in South Africa have outlined steps Nigerian and South African authorities need to take to end xenophobia in the rainbow country.
One of these is that South African President Cyril Ramaphosa should offer a "sincere public apology to Nigeria, other countries affected by the attacks and the entire continent for the tragic hostility and harm perpetrated against their citizens."
These demands were highlighted in a communique issued after a meeting of the Nigerian Community Western Cape (NCWC) with Oby Ezekwesili, a former Nigerian minister.
The meeting on the sidelines of the World Economic Forum (WEF) in Cape Town was attended by Nigerian entrepreneurs, professionals and the Nigerian community-led by Cosmos Echie.
Although Nigeria boycotted the WEF as part of its protests against xenophobic attacks on Nigerians and other Africans in South Africa, Mrs Ezekwesili, Nigeria's former minister of education and solid minerals, attended the event, an action that drew her public backlash.